MapExpression

public class MapExpression : FunctionExpression, @unchecked Sendable

An expression that represents a map (or dictionary) of key-value pairs.

MapExpression is used to construct a map from a dictionary of String keys and Sendable values. The values can be literals (like numbers and strings) or other Expression instances, allowing for the creation of dynamic nested objects within a pipeline.

Example:

MapExpression([
  "genre": Field("genre"),
  "rating": Field("rating").multiply(10),
  "nestedArray": ArrayExpression([Field("title")]),
  "nestedMap": MapExpression(["published": Field("published")]),
]).as("metadata")